Yonezaki is first mentioned in Crows when he enters Suzuran from Ida Mid and beats fellow freshmen Kakimoto from 5th Mid[1]. Yonezaki has already got a following and in the shadows, Masa and Hideyoshi were discussing how Yonezaki is in their class and how he will be the first to kneel to them [2]. In their class, Hideyoshi tells Yonezaki that class B is either his or belongs to himself. One of Yonezaki's followers got up and angrily tells Hideyoshi to repeat what he said [3]. Masa gets in and knocks down Yonezaki's follower and beats him on the ground until Hideyoshi tells him to stop [4]. Yonezaki and Hideyoshi then engage in a fight where Hideyoshi beats Yonezaki by knocking him through the class window [5].

When Yonezaki returns to school, he is met by Udo, who told him that he needs to talk to him. Yonezaki tells Udo that if he thinks he can collect the 6 buttons, then he should just quit as there is no way he could beat Hideyoshi. Udo tells him that he isn't planning to fight Hideyoshi, but he will get the 6 buttons. Yonezaki starts to feel uncomfortable. Yonezaki saw that Udo, Morita from class A, Takeuchi from class D and Tajima from class E are planning to gang up Hideyoshi, Gunji and Zetton to become the rulers of the freshmen [6]. Udo tells Yonezaki that he wouldn't take lying down with one of those three as the strongest of the freshmen. Udo says to Yonezaki that he wont be shit for the next three years. An angry Yonezaki pushes off Udo and tells him he won't play his stupid games and told him to think about who he is talking to next time. Udo and Takeuchi tell Yonezaki that he will have to watch his back and that he will regret his decision [7]. Yonezaki turns to them and says that he might be bad, but he isn't rotten [8].

His outlook on the men competing in the war had changed, and it was shown that he became closer to the rest of them progressively to the point of them hanging out daily together with their seniors.

From a distance, Yonezaki saw Gunji get jumped by Udo and his group. Yonezaki turns around and walks away, thinking to himself that it doesn't concern him. While walking away, Yonezaki bumps into Hideyoshi and Masa. Hideyoshi tells Yonezaki that he better not skip PE as they are playing soccer [9]. Masa said he is his teams goalie and needs him against this asshole (pointing to Hideyoshi). Yonezaki then tells them the Gunji was jumped by Udo and he is using a group to jump the three of them . A shocked Hideyoshi jumps off the stairs and was told that they are behind the gym [10]. After Hideyoshi runs after ambush, Masa asked why did Yonezaki help, to which Yonezaki says he has no reason, to which Masa smiles [11].

After the weekend, Yonezaki walks around Suzuran looking for Gunji. Finding Gunji, Yonezaki offers him a cigarette and asks him who won between Hideyoshi and Zetton as they fought on Saturday and that they are absent from school today [12]. Gunji tells him that Zetton acquired all 6 buttons, much to the shock of Yonezaki who was surprised that Hideyoshi lost [13]. Yonezaki said that with Zetton being Bouya's lackey, no one will challenge the senior leader at the rooftop, to which Gunji says the show's not over yet, which Gunji implies that Zetton will challenge Bouya [14]. Two days later, Yonezaki bumps into Masa who is shouting after Hideyoshi who walked away not interested to see Bouya and Zetton fight. Yonezaki says to let him be as he has a lot of pride, and that he must be frustrated he didn't reach the top [15].

During his third year, Yonezaki was considered a lone wolf. However, he was often seen rolling with Zetton or Gunji. Being a very low key individual, Yonezaki was respected for his keen intellect by Suzuran as well as rival school delinquents alike, despite not being among the strongest of his peers, the fact that he was formerly the head of Ida Mid likely meant he was among the smartest of his fellow senior leaders, this led many to fear his ability of planning attacks, with even the likes of King Joe making it a priority to eliminate him before going to all out war with Suzuran.